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Biomedical subjects

C M Croce

Publications and source records attributed to C M Croce.

At least 487 records · Page 27Linked to original sources
PubMed1976

Assignment of the structural gene for human beta glucuronidase to chromosome 7 and tetrameric association of subunits in the enzyme molecule.

The structural locus for human beta glucuronidase is assigned to chromosome 7, a localization based upon concordant segregation of the expression of the human enzyme and the presence of human chromosome 7 in somatic cell hybrid clones derived independently from fusions of different human and mouse cells. Hybrid clones containing only human chromosome 7 are included in this study. Electrophoresis of beta glucuronidase also has revealed that human beta glucuronidase has a tetrametric structure.

Animals↗
PubMed1975

Tumorigenicity of mouse-human diploid hybrids in nude mice.

Somatic cell hybrids between normal mouse cells and simian virus 40 (SV40)-transformed human cells, which contained a diploid complement of mouse chromosomes and the human chromosome 7 carrying the genome of SV40, were tumorigenic in nude mice. One single copy of human chromosome 7 per hybrid cell appeared to be sufficient for the tumorigenicity of the hybrids.

Animals↗
PubMed1975

Somatic cell hybrids between mouse peritoneal macrophages and simian-virus-40-transformed human cells: II. Presence of human chromosome 7 carrying simin virus 40 genome in cells of tumors induced by hybrid cells.

Cells derived from tumors induced in "nude" mice after injection of cells that were hybrids between mouse peritoneal macrophages and simian virus 40 (SV40)-transformed human cells were found to retain the human chromosome 7 carrying the SV40 genome, and indicate that the presence of human chromosome 7 carrying the SV40 genome is responsible for the expression of the tumorigenic phenotype in the hybrid cells.

Animals↗
PubMed1975

Assignment of gene(s) for cell transformation to human chromosome 7 carrying the simian virus 40 genome.

Somatic cell hybrid clones between either C57BL/6 or Balb/c mouse peritoneal macrophages and two different simian virus 40 (SV40)-transformed human cell lines deficient in hypoxanthine phosphoribosyltransferase (EC 2.4.2.8; IMP:pyrophosphate phosphoribosyltransferase) were obtained in hypoxanthine-aminopterin-thymidine selective medium. All the hybrid cell clones contained the human chromosome 7, which carries the SV40 genome, and were SV40 tumor (T)-antigen positive. No hybrid cell clones studied displayed the density-dependent inhibition of cell growth characteristic of normal cells; all clones had a high saturation density and gave origin to cell colonies when plated in soft agar. Since the expression of the transformed phenotype was always associated with the presence of the human chromosome 7, which carries the SV40 genome, it is concluded that this chromosome contains gene(s) [Tr gene(s)] coding for "transforming factor(s)."

Animals↗
PubMed1975

Genetics of cell transformation by simian virus 40.

The results described in this paper indicate that the integration of the SV40 genome into human chromosome 7 results in the transformation of the human cells and in the expression of SV40-induced antigens. If integration of the SV40 genome in human chromosomes other than 7 ever occurs, it does not result in cell transformation and the expression of the virus-induced antigens. The expression of the SV40 T antigen in different monkey cells transformed by an adeno 7-SV40 hybrid is also related to a specific monkey chromosome. Somatic cell hybrids between normal nondividing mouse cells and SV40-transformed human cells behave as transformed cells and contain, without exception, the human chromosome 7 carrying the SV40 genome. Since no segregation into SV40 T antigen-negative hybrid clones was observed in these hybrids, it is inferred that the presence of the human chromosome 7 carrying the SV40 genome in the hybrids is mandatory for cell division.

Antigens, Neoplasm↗
PubMed1975

Confirmation of the synteny of the human genes for mannose phosphate isomerase and pyruvate kinase and of their assignment to chromosome 15.

The synteny of human mannose phosphate isomerase and pyruvate kinase and the assignment of the genes for these two enzymes to chromosome 15 were confirmed by analysis of 43 independently derived human-mouse hybrid clones. Hybrids between mouse cells deficient in hypoxanthine-guanine phosphoribosyltransferase and human fibroblasts carrying an X/15 chromosome translocation were also included in this study.

Animals↗
PubMed1975

Reversion in expression of hypoxanthine-guanine phosphoribosyl transferase following cell hybridization.

Hybridization of mutant cell lines deficient in hypoxanthine-guanine phosphoribosyl transferase (HGPRT; E.C.: 2.4.2.8) from a variety of established rodent sources with HGPRT plus human cells yielded progeny cells which grew in selective medium containing hypoxanthine, aminopterin and thymidine (HAT). The same result was obtained when the human cell used was an HGPRT minus transformed line derived from a patient with the Lesch-Nyhan syndrome. Electrophoretic analysis indicated that all HAT-resistant progeny clones contained an active HGPRT enzyme which was indistinguishable from the wild type enzyme of the corresponding normal rodent cells. In contrast, no HAT-resistant cells have been obtained when the same HGPRT minus rodent cells were subjected to fusion processes in the absence of human cells or when they fused with similarly derived HGPRT minus mutant cells of other rodents. Reversion in expression of the rodent gene for HGPRT was detected in clones which retained one or more human chromosomes and in clones which contained no detectable human chromosomal material. The observed re-expression of rodent HGPRT in HAT-resistant clones suggests that HGPRT plus as well as HGPRT minus human cells contributed a factor which determined the expression of respective rodent structural genes for HGPRT. In contrast, HGPRT minus rodent cells were unable to induce the synthesis or normal HGPRT in the cells derived from the patient with the Lesch-Nyhan syndrome.

Aminopterin↗
PubMed1974

Somatic cell hybrids between mouse peritoneal macrophages and SV40-transformed human cells. I. Positive control of the transformed phenotype by the human chromosome 7 carrying the SV40 genome.

Fusion of mouse peritoneal macrophages with SV40-transformed human cells, deficient in hypoxanthine guanine phosphoribosyltransferase, resulted in the formation of transformed somatic cell hybrids which contained, without exception, the human chromosome 7 carrying the SV40 genome. It is postulated that the hybridization of mouse nondividing cells with human cancer cells could permit the identification of the human "oncogenic" chromosome(s) present in human cancer cells, since such chromosome(s) should be retained by the totality of the mouse-human hybrid cells.

Animals↗
PubMed1974

Positive control of transformed phenotype in hybrids between SV40-transformed and normal human cells.

Somatic cell hybrids have been obtained between SV40-transformed Lesch-Nyhan fibroblasts, which are deficient in hypoxanthine-guanine phosphoribosyltransferase (HGPRT) and display glucose-6-phosphate dehydrogenase A (G6PD-A) activity, and late-passage HGPRT-positive W138 human embryo fibroblasts, which display G6PD-B activity. The human-human hybrid clones, which display G6PD-A and G6PD-B and heteropolymers of the two enzyme forms, have the same growth characteristic as the SV40-transformed parental cells and behave as continuous cell lines. The SV40 tumor antigen, the gene for which has been assigned to human chromosome 7, is present in all clones examined.

Antigens, Neoplasm↗
PubMed1974

Concordant segregation of the expression of SV40 T antigen and human chromosome 7 in mouse-human hybrid subclones.

Subcloning of Simian virus 40 (SV40) T antigen-positive mouse-human hybrids, derived from the fusion of mouse cells deficient in thymidine kinase with SV40-transformed Lesch Nyhan fibroblasts, resulted in their segregation into T antigen-positive and negative subclones. Positive correlation between the presence of human chromosome 7 and the expression of SV40 T antigen was established in the subclones examined. These results negate the possibility of a transfer of the SV40 genome to a mouse chromosome.

Animals↗